WO2007010806A1

WO2007010806A1 - Progressive refractive power lens

Info

Publication number: WO2007010806A1
Application number: PCT/JP2006/313922
Authority: WO
Inventors: Mitsuhiro Yanari
Original assignee: Nikon-Essilor Co., Ltd.
Priority date: 2005-07-21
Filing date: 2006-07-06
Publication date: 2007-01-25
Also published as: JPWO2007010806A1; JP5000505B2

Abstract

A progressive refractive power lens easily capable of measuring the power of the lens by an optician store or a user despite satisfactory improvement in optical performance while the user wears. The lens comprises, along a main fixation line (MM') that divides a lens refractive plane into a nose side area and an ear side area, a distant unit (F) comparatively suitable for distant viewing, a reading unit (N) comparatively suitable for near viewing, and a progressive unit (P) for continuously connecting the plane refractive power of the distant unit and the plane refractive power of the reading unit, when the lens is worn. An average value of absolute values of differences between a surface astigmatic difference component generated by the prescribed aspherical surface formed to correct optical performance at a lens-transmitting light beam and a surface astigmatic difference component generated by a spherical or toric surface required for prescribed power correction is up to a specified value over a specified area in the vicinity of and including a measurement reference point (OF).

Description

Meiji book Progressive power lens Technical field

The present invention relates to a progressive-power lens, and more particularly, to a progressive-power lens that is used as an aid to eye accommodation. Background art

Single vision lenses, bifocal lenses, progressive power lenses, etc. are used to correct presbyopia. A progressive-power lens is located at the upper part of the lens when worn and is suitable for far-distance viewing (hereinafter also referred to as “distance part”). Near vision area suitable for vision (hereinafter also referred to as “near vision area”) and progressive area that is located between the distance vision area and the near vision area and continuously connects both surface refractive powers ( (Hereinafter also referred to as “progressive part”).

In the present invention, the measurement reference point for measuring the lens power at the distance portion is referred to as “distance reference point”, and the measurement reference point for measuring the lens power at the near portion is referred to as “near reference point”. Call. The straight line or curve that passes through the distance reference point and the near reference point and divides the refracting surface of the progressive surface into a nose region and an ear region is called a “main gaze line”. The main line of sight is used as a reference line that represents specifications such as the addition power of a progressive-power lens, and is used as an important reference line when designing a progressive surface (progressive refractive surface).

Conventional progressive-power lenses use semi-finished lenses (hereinafter referred to as “semi-finished lenses”) whose progressive-refractive surfaces have been processed in advance. That is, the spectacle lens is created by processing the prescription surface of the semi-finished lens into a spherical shape or a toric surface shape according to the spherical power or astigmatic power of the spectacle wearer.

Usually, the surface shape of the progressive refractive surface in a semi-finished lens is The surface shape is set so as to obtain the most preferable optical performance at a specific prescription power within the range. Therefore, if this specific power is used as the reference power of the semi-finished lens, the optical performance of the lens at the prescription power near the reference power is good, but the decrease in the optical performance is avoided as the prescription power deviates from the reference power. There was a drawback of not. However, in recent years, with the development of aspherical processing technology, it has become possible to freely process a lens surface into an aspherical shape, particularly into a complex aspherical shape such as a free-form surface within a short time.

As a result, taking into account the prescription and usage conditions of the wearer, a progressive power lens with aspherical prescription surfaces, which were previously spherical or toric, has been commercialized. The optical performance of this product has been greatly improved over a wide frequency range without depending on the prescription power. In this case, the aspherical surface used for the prescription surface is generally a free-form surface having no symmetry, such as a polynomial aspherical surface, or a spline surface shape such as a bicubic spline or B-spline.

A double-sided aspherical progressive refraction calendar in which not only the progressive refraction surface but also the prescription surface is aspherical is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-034 1986. Generally, in a progressive-power lens, the power of a lens at at least one of a distance reference point and a near reference point is measured by a measuring instrument called a lens meter. In conventional progressive-power lenses, the prescription surface is entirely spherical or toric, so the prescription power of the wearer and the spherical power and astigmatism power measured at the measurement reference point by the lens holder There was a substantial agreement. However, a progressive bending lens with an aspheric prescription surface that places importance on optical performance in the wearing state causes an astigmatism difference at the measurement reference point because the prescription surface is aspherical. As a result, spherical power and astigmatism power different from the prescription power are displayed in the measurement with the lens meter. Moreover, as the amount of aspherical surface given to the prescription surface increases, the difference between the spherical power and astigmatism power measured by the lens unit and the prescription power of the wearer tends to increase. For this reason, manufacturers have introduced special lens meters that measure the frequency in the wearing state, or the frequency obtained by measuring with a general lens meter as the measurement theoretical frequency separately from the original prescription frequency. It is also written together. The combination of the prescription frequency and the measurement theory frequency is called “double notation”. Actually, it is difficult to introduce a special lens meter that can measure the frequency in the wearing state in general eyeglass stores, so the measurement method using double notation is the mainstream.

By the way, in the case of a double-sided aspherical progressive-power lens with an aspheric prescription surface, the measurement position by the lens meter compared to a conventional progressive-power lens with a spherical or toric surface treatment surface. The measurement error due to the alignment accuracy is large. Furthermore, the difference between the prescription power displayed in double notation and the measurement theoretical power is not necessarily constant, and varies depending on various prescription conditions such as spherical power, diopter power, astigmatic axis, and addition power. Therefore, when measuring the power of a progressive power lens with double notation, it is necessary to check all the measurement theoretical powers displayed by the manufacturer for each lens. ·

In other words, power measurement of a progressive power lens with double notation requires a complicated procedure that is different from the conventional progressive power lens, and when a person unfamiliar with measurement or a large number of lenses is measured. Requires more time and effort than conventional progressive-power lenses to obtain accurate measurement results. Therefore, some spectacle stores and users have requested a double-sided aspherical progressive-power lens that makes it easier to measure the power of lenses without focusing on optical performance alone. Yes.

Therefore, in order to solve the problem that the prescription power and the measurement power are different in the conventional double-sided aspherical progressive-power lens disclosed in Japanese Patent Laid-Open No. 2 0 4-3 4 4 0 8 6 An area where no surface astigmatism occurs is provided in a part of the linear portion along the main line of sight on the prescription surface.

Specifically, the main gaze on the prescription surface is not visible in some areas of the distance portion including the main gaze that is discarded as an unnecessary part when the lens is actually processed into a frame shape. It is configured so that the same measurement power as the prescription power can be obtained by measuring the power of the lens in the area where the point difference does not occur. However, according to the study by the present inventor, in the progressive power lens that was evaluated by the surface power distribution as in the past, the evaluation based on the shape of the main gazing line was important. For a double-sided aspherical progressive-power lens that focuses on optical performance and aspherics on both sides, it is found that it is not sufficient to specify the surface shape of some linear parts of the main line of sight. It was.

In other words, in a progressive-power lens having a progressive surface using a free-form surface, in order to improve the optical performance over the entire lens, the prescription surface also has symmetry such as a high-order polynomial or spline. No aspheric shape is required. However, since the aspherical shape without such symmetry has a high degree of surface freedom, it is not possible to specify the surface shape of the adjacent region simply by defining the surface shape on the main line of sight. In other words, even if the prescription surface on the main line of sight is set to a spherical shape, the amount of aspherical surface at a position slightly away from the main line of sight increases and the contribution to optical performance is unavoidably fluctuated. There is also. Therefore, at least in the region where the power of the lens is measured, it is essential to control the shape of the surface. However, in the conventional technique disclosed in Japanese Patent Laid-Open No. 2 0 4-3 4 10 8 86 There is no clear disclosure regarding the surface shape in the region.

In addition, the power measurement of the original lens is performed to check whether the lens has been created correctly as prescribed by the wearer. Therefore, in general spectacle lenses as well as progressive-power lenses, measurement reference points are arranged in the vicinity of the geometric center of the lens or at the most important position for wearing the lens. In other words, as described in Japanese Patent Laid-Open No. 2 0 4-3 4 1 0 8 6, if the shape on the main meridian (main gaze line) outside the frame shape does not cause a plane astigmatism, Although it is possible to obtain the same measurement power as the prescription power while keeping the influence on the optical performance at the time small, the measurement power obtained by the conventional technology of JP-A 2 0 0 4-3 4 1 0 8 6 is Originally required Unlike the purpose of lens power measurement, it is not appropriate. Disclosure of the invention

The present invention has been made in view of the above-mentioned problems, and it is possible to easily perform lens power measurement by a spectacle store or a user even though the optical performance in the wearing state is improved satisfactorily. An object of the present invention is to provide a progressive power lens that can be used. In order to solve the above problems, in the present invention, a far-field region that is relatively suitable for far-distance viewing along a main gaze line that divides the refractive surface of the lens into a nose-side region and an ear-side region in the wearing state A near vision area relatively suitable for near vision with respect to the distance vision area, and a surface refractive power of the distance vision area and the near distance between the distance vision area and the near vision area. In a progressive refraction calendar having a progressive area that continuously connects the surface power of the application area,

The prescription surface formed to correct the optical performance of the transmitted light of the lens has an aspheric shape, and is generated by the surface astigmatism component generated by the prescription surface and the spherical surface or toric surface necessary for correcting the prescription power Progressive refraction characterized in that the average value of the absolute value of the difference from the surface astigmatic difference component is less than or equal to a predetermined value over a predetermined area in the vicinity including the measurement reference point for measuring the lens power Provide a power lens.

In this invention, the prescription surface formed in order to correct | amend the optical performance in the transmitted light of a lens has aspherical shape. And the average of the absolute values of the difference between the surface astigmatism component generated by the aspherical shape of the prescription surface and the surface astigmatism component generated by the spherical or curly surface required for correcting the prescription power "The average value of the surface astigmatism component that is substantially generated by the aspherical prescription surface" or "the average value of the surface astigmatism component") includes the measurement reference point for measuring the lens power. The value is kept below a predetermined value over a predetermined area in the vicinity.

Therefore, the measurement reference point is set using, for example, a lens meter, even though the optical performance in the wearing state is corrected by making the prescription surface aspherical. By measuring as a reference, it is possible to obtain a measurement frequency almost the same as the prescription frequency. That is, in the progressive-power lens of the present invention, although the optical performance in the wearing state is satisfactorily improved in consideration of the prescription and use conditions of the wearer, the lens power by the spectacle store or the user is one. Measurement can be performed easily. Brief Description of Drawings

FIG. 1 is a diagram schematically showing a configuration of a progressive-power lens according to an embodiment of the present invention.

FIG. 2 is a diagram showing the astigmatism distribution in the transmitted light of the conventional progressive-power lens according to the comparative example of the first example.

FIG. 3 is a diagram showing the astigmatism distribution in the transmitted light of the progressive addition lens according to the first example.

FIG. 4 is a diagram showing a distribution of surface astigmatism components substantially generated by making the prescription surface aspherical of the progressive-power lens according to the first example.

FIG. 5 is a diagram showing the astigmatism distribution in the transmitted light of the conventional progressive-power lens according to the comparative example of the second example.

FIG. 6 is a diagram showing the astigmatism distribution in the transmitted light of the progressive addition lens according to the second example.

FIG. 7 is a diagram showing a distribution of surface astigmatism components substantially generated by making the prescription surface of the progressive-power lens according to the second example aspherical. BEST MODE FOR CARRYING OUT THE INVENTION

Prior to specific description of the embodiments of the present invention, the basic configuration and operation of the present invention will be described. Frequency measurement with a lens meter is performed with reference to a measurement reference point on the lens surface. Actually, measurement is performed in a measurement area with a certain area, not a point. In addition, this measurement area includes the type of lens meter and the lens to be measured. T / JP2006 / 313922

It varies in size (area) depending on the specifications of 7. For this reason, in the present invention, a predetermined area in the vicinity including a measurement reference point where the average value of the surface astigmatism component generated substantially by the aspherical surface of the prescription surface should be kept below a predetermined value is used for the measurement of the lens meter. It is necessary to decide in consideration of the necessary area (hereinafter referred to as “measurement area”). In other words, if only frequency measurement is considered, it is more effective that the predetermined area where the average value of the above-mentioned astigmatic difference component is not more than a predetermined value is as wide as possible. Optical performance is degraded. For this reason, in order to achieve the object of the present invention, the predetermined region in the vicinity including the measurement reference point should be determined in consideration of these various conditions. In the present invention, when importance is attached to the optical performance in the wearing state, the predetermined area in the vicinity including the measurement reference point where the average value of the surface astigmatic difference component is equal to or less than the predetermined value extends from the measurement reference point in the horizontal direction of the lens. Where X (mm) is the distance from the measurement reference point in the vertical direction of the lens, y (mm), I (x ² + y ² ) ^{l / 2} l≤ 2.5 0 (mm) It must be an area that satisfies the conditions

desirable.

Further, in the present invention, when considering the balance between the improvement of optical performance in the wearing state and the ease of frequency measurement, the predetermined region where the average value of the surface astigmatic difference component should be kept below a predetermined value is I (x ² + y ² ) ^{1/2 I} ≤ 4.0 0 (mm) is desirable.

Furthermore, in the present invention, I (x ² + y ² ) ^1/2 I≤ 5.0 0 (mm) when importance is attached to the ease of frequency measurement in consideration of the effect of the accuracy of lens meter measurement alignment. It is desirable that the region satisfies the condition (1).

By the way, there is always a surface astigmatism on the toric surface, but this is originally a surface astigmatism necessary for astigmatism correction, and is not given to improve optical performance. Therefore, in the present invention, the surface astigmatism necessary for correcting astigmatism is considered separately from the surface astigmatism generated by making the prescription surface aspherical. That is, as described above, in the present invention, the surface astigmatism component generated substantially by the aspherical surface of the prescription surface is reduced. It is expressed as the absolute value of the difference between the surface astigmatism at any coordinate of the spheroidized prescription surface and the surface astigmatism at the coordinate of the spherical or toric surface necessary for correcting the prescription power.

That is, AS (X, y) is the surface astigmatism difference at an arbitrary coordinate (X, y) on the prescription surface, and the corresponding spherical surface or toric surface is necessary to correct the prescription power before being aspherical. The plane astigmatism at the coordinates (X, y) is C (x, y), and the surface astigmatism component that is substantially generated at the coordinates (X, y) due to the aspherical surface of the prescription surface is AAS (x , y), AAS (x, y) is expressed by the following equation (1).

△ AS (, y) = I AS (x, y) One C (x, y) I (1)

Since the power is measured with a lens meter based on light rays that are incident almost perpendicular to the prescription surface, the distribution of the surface astigmatism component within the measurement area almost directly affects the measurement power. Therefore, in the present invention, the average value of the surface astigmatism component that is substantially generated by making the prescription surface aspherical is Δ AS av, and the average value AASav is suppressed to a predetermined value or less to achieve the object of the present invention. Have achieved. Table 1 below is a table established in IS Standard 8980-2: 2004 (E), which is an ISO standard for progressive-power spectacle lenses for correcting bending, with astigmatism bending at the measurement reference point. It is a table | surface which shows the tolerance with respect to the display value of force.

table 1

Tolerance of astigmatic power to the displayed value Absolute power of both major meridians

Main meridian refractive power Tolerance 0.00 or more Over 0.75 Over 4.00 Over 6.00

0.75 or less 4.00 or less 6.00 or less

0.00 or more 6.00 or less ± 0.12 ± 0.12 ± 0.18 ± 0.18 ± 0.25

Over 6.00 and under 9.00 ± 0.18 ± 0.18 ± 0.18 ± 0.18 ± 0.25

Over 9.00 and under 12.00 ± 0.18 ± 0.18 ± 0.18 ± 0.25 ± 0.25

Over 12.00 and under 20.00 ± 0.25 ± 0.18 ± 0.25 ± 0.25 ± 0.25

Over 20.00 ± 0.37 ± 0.25 ± 0.25 ± 0.37 ± 0.37 All the numerical values listed in Table 1 are diopters. Also, the “larger principal meridian power in absolute value” described in Table 1 means that when the spherical power is indicated by S and the astigmatic power is indicated by C, both principal meridians It means the larger value of the absolute value of refractive power IS 1 and 1 S + CI. When measuring frequency with a lens meter, it is common to use official standards such as the ISO standard.

In other words, if the amount of deviation of the measured power from the lens lens relative to the prescription power is less than the tolerance value (tolerance) set in the ISO standard, it is judged that the prescription power and the measured power are practically equal. Can do. Therefore, in the present invention, the object of the present invention can be achieved if the average value AASav is suppressed to be equal to or smaller than the tolerance set in the ISO standard shown in Table 1. However, when considering the influence of the progressive surface on the measurement frequency, the average value AASav is preferably 75% or less of the allowable value in Table 1.

ΔASav is more preferably 50% or less of the allowable value in Table 1. As can be seen with reference to Table 1, it is desirable that the tolerance value for frequency measurement varies depending on the prescription frequency and the astigmatism frequency, but because of the simplification of design and manufacturing practices, the tolerance value of the average value Δ AS av It is also possible to make this constant without depending on the wearer's prescription. In that case, the tolerance value of the average value AASav can be selected and determined from the tolerance values listed in Table 1, but according to the study of the present inventor, the optical performance in the wearing state is emphasized. In some cases, it is desirable to satisfy AASav ≤ 0.15 (diop evening), and when the optical performance in the wearing state is more important, it is desirable to satisfy AASav ≤ 0.12 (diopter).

In the present invention, it is desirable to satisfy AASav≤0.10 (diop evening) when considering the balance between the improvement of optical performance in the wearing state and the ease of frequency measurement, and AASav≤0. It is even more desirable to satisfy 09 (Diop Yuichi). Furthermore, in the present invention, when emphasizing ease of frequency measurement,

△ It is desirable to satisfy ASav ≤ 0.06 (diop evening). In the present invention, the predetermined region in the vicinity including the measurement reference point where the average value ΔAS av of the surface astigmatism component should be kept below a predetermined value is substantially spherical or toric. Is preferred. If an optician or user places more emphasis on measuring power with a lens meter than improving optical performance in transmitted light, i.e., the prescription power and the measured power are substantially matched without taking into account the tolerances of the standard. It is effective to make the prescription surface substantially spherical or toric in the predetermined area. According to the study of the present inventor, even if the entire measurement area of the lens base is not substantially spherical or toric, the constant area of the central portion in the measurement area is substantially spherical. It has also been found that the object of the present invention can be achieved by forming a toric surface shape. Therefore, in the area near the measurement reference point that is substantially spherical or toric, the distance from the measurement reference point in the horizontal direction of the lens is X (mm), and the vertical direction of the lens from the measurement reference point I (x ² + y ² ) ^1/2 I≤ 1. 75 (mm)

It is desirable that the region satisfies this condition. In addition, in order to make the prescription power and the measurement power better match, the neighboring region including the measurement reference point which is substantially spherical or toric surface shape is I (x ² + y ² ) ^{| / 2} 1≤ 2. 50 (mm)

It is desirable that the region satisfies the condition of I (x ² + y ² ) ^Ι7 Ί≤ 4.00 (mm).

With a typical lens meter, it is very difficult to accurately measure a surface astigmatism component smaller than 0.06D (Diop Yuichi), and it is also practical to measure a surface astigmatism component below 0.03D. It is said that it is impossible. Therefore, it is considered that the practical refractive power measurement resolution in the lens unit is 0.03D or more. For this reason, if the surface astigmatism component in the adjacent region including the measurement reference point is 0.03 D or less, which is the same as the measurement resolution of the lens meter, the actual measurement will be spherical or torsional. It can be regarded as equivalent to the mask surface.

Further, in the present invention, at least one of the size and shape of the predetermined area in the vicinity including the measurement reference point where the average value ΔAS av of the surface astigmatism component should be kept below a predetermined value is Can be determined based on at least one of the following: preferable. In a double-sided aspherical progressive power lens with an aspheric prescription surface as in the present invention, the prespherical shape of the prescription surface is spherical, astigmatic, astigmatic, It varies greatly depending on the wearer's prescription and usage conditions such as addition, inset angle and prism prescription. .

In addition, the measurement conditions of the lens meter, which is a measuring instrument, can be measured even if the measuring beam is a circular beam with a diameter of 5 mm. Some manufacturers manufacture lens meters that have a rectangular light beam. Even with the same manufacturer, the conditions vary depending on the manufacturer and measurement method, such as the size and shape of the measurement light beam differing between the manual lens meter and the automatic lens meter. Therefore, the technology according to the present invention is not applied to all lenses under the same conditions, but at least one of the prescription and usage conditions of the wearer, the product specifications, the frequency measurement method, and the measurement instrument specifications. By taking into account the average value AAS av and determining the size and shape of the predetermined area including the measurement reference point that should be kept below the predetermined value, both superior optical performance and ease of frequency measurement can be achieved. It can be obtained.

In the present invention, at least a second derivative of a function representing the surface shape of the prescription surface (for example, a function representing the surface shape in the design of the prescription surface, a function obtained by fitting the actual surface shape of the prescription surface). It is preferable that the process is continuous over almost the entire prescription surface. With this configuration, it is possible to obtain good continuity in appearance and good optical performance in transmitted light, and at the same time always measure as a lens meter. 6313922

12 Stable values can be obtained.

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing the configuration of a progressive-power lens according to an embodiment of the present invention. Referring to FIG. 1, the progressive-power lens of this embodiment is suitable for relatively far vision along the main sight line MM 'that divides the refractive surface of the lens into a nose side region and an ear side region in the wearing state. The distance power of the distance F and the surface refraction of the near area N between the distance area F and the near area N And a progressive part P that continuously connects the force.

The main line of sight MM 'is the distance reference point (distance center) 0F, the distance eye point E, the geometric center OG of the lens surface, and the near area N measurement standard. This is a reference line that passes through ON. In each example of the present embodiment, a progressive surface is disposed on the outer surface (the outer surface opposite to the eye), and a prescription surface is disposed on the inner surface (the inner surface on the eye side). The distance reference point OF, which is the measurement reference point of the distance portion F, is located 8 mm above the geometric center OG along the main line of sight MM '. The outer diameter (diameter) of each example lens is 70 mm.

[First Example]

FIG. 2 is a diagram showing the astigmatism distribution in the transmitted light of the conventional progressive-power lens according to the comparative example of the first example. In the conventional progressive-power lens according to the comparative example in FIG. 2, the spherical power S = l. 00 (diop evening), the astigmatic degree C = 0.00 (diop evening), and the addition ADD = 2. 00 (diopter), prescription curve BC = 3.70 (diopter), and lens refractive index ne = l. 60. Referring to FIG. 2, in the comparative progressive-power lens according to the prior art, in the distance portion F and the near portion N, the astigmatism is 0.5D (diop evening) or less, that is, clear vision. The area is getting narrower.

FIG. 3 is a diagram showing the astigmatism distribution in the transmitted light of the progressive addition lens according to the first example. The progressive-power lens according to the first example is the same as the comparative example in FIG. (Spherical power, astigmatism power, addition power, prescription base curve, refractive index), but the inner surface, which is the prescription surface, is aspherical in order to improve the optical performance of transmitted light. Referring to FIG. 3, in the progressive-power lens of the first embodiment according to the present invention, as compared with the comparative example of FIG. ^2, the clear vision area of the distance portion F and the near portion N are both good improvement It has been done.

FIG. 4 is a diagram showing a distribution of surface astigmatism components substantially generated by making the prescription surface aspherical of the progressive-power lens according to the first example. In the first embodiment, an optical surface improvement as shown in FIG. 3 is achieved by applying an aspheric surface having a surface astigmatism component distribution as shown in FIG. 4 to the prescription surface. Yes. Table 2 below shows the distribution of the surface astigmatism component that is substantially generated by asphericalization of the neighboring area including the measurement reference point 〇 F on the prescription surface of the progressive-power lens according to the first example. It is a table shown. Table 2

-10.0 -9.0 -8.0 -7.0 -6.0 -5.0 -4.0 -3,0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 3.0 9.0 10.0

10.0 0.18 0.16 0.15 0.13 0.12 0.10 0.09 0.08 0.07 0.06 0.06 0.07 0.07 0.08 0.09 0.10 0.1 1 0.12 0.13 0.14 0.15

9.0 0.18 0.16 0.15 0.13 0.12 0.10 0.09 0.08 0.07 0.06 0.06 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15

8.0 0.17 0.16 0.15 0.13 0.12 0.10 0.09 0.08 0.07 0.06 0.06 0.06 0.06 0.07 0.08 0.09 0.10 0.11 0.13 0.14 0.14

7.0 0.17 0.16 0.14 0.13 0.12 0.10 0.09 0.08 0.07 0.06 0.05 0.06 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14

6.0 0.17 0.16 0.14 0.13 0.12 0.10 0.09 0.08 0.07 0.06 0.06 0.06 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14

5.0 0.17 0.15 0.14 0.13 0.12 0.10 0.09 0.08 0.07 0.06 0.06 0.06 0.06 0.07 0.07 0.08 0.09 0.10 0.1 1 0,12 0.13

4.0 0.16 0.15 0.14 0.13 0.12 0.11 0.09 0.08 0.07 0.06 0.06 0.06 0.06 0.07 0.07 0.08 0.09 0.10 0.11 0.12 0.13

3.0 0.16 0.15 0.14 0.13 0.12 0.11 0.10 0.08 0.08 0.07 0.06 0.06 0.06 0.07 0.07 0.08 0.09 0.10 0.11 0.11 0.12

2.0 0.16 0.15 0.14 0.13 0.12 0.11 0.10 0.09 0.08 0.07 0.07 0.06 0.07 0.07 0.07 0.08 0.09 0.10 0.10 0.11 0.12

1.0 0.16 0.15 0.14 0.13 0.12 0.11 0.10 0.09 0.08 0.08 0.07 0.07 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.11 0.11

0.0 0.15 0.15 0.14 0.13 0.12 0.11 0.11 0.10 0.09 0.08 0.08 0.08 0.07 0.08 0.08 0.08 0.09 0.09 0.1O 0.11 0.11

-1.0 0.15 0.15 0.14 0.13 0.13 0.12 0.1 1 0.10 0.10 0.09 0.09 0.08 0.08 0.08 0.08 0.09 0.09 0.09 0.10 0.10 0.11

-2.0 0.15 0.15 0.14 0.14 0.13 0.12 0.12 0.11 0.10 0.10 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.10 0.10 0.10 0.11 One 3.0 0.15 0.15 0.15 0.14 0.13 0.13 0.12 0.12 0.11 0.10 0.10 0.10 0.09 0.09 0.09 0.09 0.10 0.10 0.10 0.10 0.10

-4.0 0.16 0.15 0.15 0.14 0.14 0.13 0.13 0.12 0.12 0.11 0.11 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10

-5.0 0.16 0.16 0.15 0.15 0.15 0.14 0.14 0.13 0.13 0.12 0.12 0.11 0.11 0.11 0.11 0.11 0.10 0.10 0.10 0. 0 0.11

-6.0 0.16 0.16 0.16 0.16 0.15 0.15 0.14 0.14 0.13 0.13 0.13 0.12 0.12 0.12 0.11 0.11 0.11 0.11 0.11 0.11 0.11

-7.0 0.17 0.17 0.16 0.16 0.16 0.16 0.15 0.15 0.14 0.14 0.13 0.13 0.13 0.12 0.12 0.12 0.12 0.11 0.11 0.11 0.11

-8.0 0.17 0.17 0.17 0.17 0.17 0.16 0.16 0.16 0.15 0.15 0.14 0.14 0.14 0.13 0.13 0.13 0.12 0.12 0.12 0.12 0.11

-9.0 0.18 0.18 0.18 0.18 0.18 0.17 0.17 0.17 0.16 0.16 0.15 0.15 0.14 0.14 0.14 0.13 0.13 0.13 0.12 0.12 0.12

-10.0 0.19 0.19 0.19 0.19 0.18 0.18 0.18 0.18 0.17 0.17 0.16 0.16 0.15 0.15 0.15 0.14 0.14 0.13 0.13 0.13 0.12 JP2006 / 313922

14 In Table 2, the horizontal axis described in the uppermost row indicates the distance X (mm) in the horizontal direction of the lens with the measurement reference point OF as the origin, and the vertical axis described in the leftmost column indicates the measurement The distance y (mm) in the vertical direction of the lens is shown with the reference point OF as the origin. As can be seen with reference to Fig. 4 and Table 2, the surface astigmatism component that is substantially generated by asphericalization of the neighboring area including the measurement reference point 〇 F is a relatively small value (diop constant). It is suppressed.

In addition, for the conventional progressive-power lens according to the comparative example of FIG. 2 and the progressive-power lens according to the first example, the measurement reference point OF is set by using a lens unit that measures with a light beam having a diameter of 5 mm. The simulation result of the measurement frequency obtained when measured as a reference is shown below.

Comparative example: Spherical power S = 1. 00 D, Astigmatic power C = 0.03D

Example: Spherical power S = 1.02D, Astigmatic power C = 0.07D

In the first embodiment according to the present invention, the spherical power and the astigmatic power as the measurement power are less than the comparative example of FIG. 2 due to the influence of the aspherical prescription surface, which is the inner surface. The value is slightly deviated from. However, referring to the ISO standard shown in Table 1, it can be seen that the deviation of the measured power from the prescription power of the wearer in the first embodiment is sufficiently within the allowable value, and there is no problem in practical use. That is, the objective of the present invention is achieved in the progressive-power lens of the first embodiment.

[Second Example]

FIG. 5 is a diagram showing the astigmatism distribution in the transmitted light of the conventional progressive-power lens according to the comparative example of the second example. In the conventional progressive-power lens according to the comparative example of FIG. 5, the spherical power S = l. 00 (diop evening), the astigmatism degree C = —2.00 (diop evening), and the astigmatic axis AX = 90 (degrees), addition ADD = 2.00 (diopter), prescription base curve BC = 3.70 (diop evening), and lens refractive index ne = l.60. Referring to FIG. 5, in the comparative progressive-power lens according to the conventional technique, the clear vision areas of the distance portion F and the near portion N are very large. 3922

15 Not only is it narrowing, but the maximum value of astigmatism is also increasing.

FIG. 6 is a diagram showing the astigmatism distribution in the transmitted light of the progressive addition lens according to the second example. The progressive power lens according to the second example has the same treatment as the comparative example in FIG. 5 (spherical power, astigmatism power, addition power, prescription base curve, refractive index), but improves optical performance in transmitted light. Therefore, the inner surface which is the prescription surface is aspherical. Referring to FIG. 6, in the progressive-power lens according to the second embodiment according to the present invention, the clear vision areas of the distance portion F and the near portion N are both very good as compared with the comparative example of FIG. As a result, the maximum value of astigmatism is getting smaller.

FIG. 7 is a diagram showing a distribution of surface astigmatism components substantially generated by making the prescription surface of the progressive addition lens according to the second example aspherical. In the second embodiment, the optical performance improvement as shown in FIG. 6 is achieved by providing the prescription surface with an aspheric surface having the distribution of the surface astigmatism component as shown in FIG. Yes. Table 3 below shows the numerical distribution of the surface astigmatism component generated substantially by the asphericalization of the nearby area including the measurement reference point OF on the prescription surface of the progressive addition lens according to the second example. It is a table shown in.

Table 3

In Table 3, as in Table 2, the horizontal axis in the uppermost row indicates the distance X (mm) in the horizontal direction of the lens with the measurement reference point OF as the origin, and 5 in the leftmost column. The vertical axis represents the distance y (mm) in the vertical direction of the lens with the measurement reference point OF as the origin. As can be seen with reference to Fig. 7 and Table 3, the surface astigmatism component that is substantially generated by asphericalization of the neighboring area including the measurement reference point OF is suppressed to almost 0 (diop evening) The surface shape is substantially equal to the toric surface.

10 For the conventional progressive-power lens according to the comparative example of FIG. 5 and the progressive-power lens according to the second example, a measurement reference point 0 F is set using a lens meter that measures light with a diameter of 5 mm. The simulation results of the measurement frequency obtained when measuring as a reference are shown below.

Comparison example: Spherical power S = l. 00D, Astigmatic power C = —2. 03D, Astigmatic axis AX =

15 90 (degrees) Example: Spherical power S = l. 0 0 D, Astigmatism power C = —2.0 3 D, Astigmatic axis AX = 9 0 (degrees)

In the second embodiment according to the present invention, the region in the vicinity including the measurement reference point OF on the prescription surface which is the inner surface has a shape substantially equal to the toric surface. As a result, the spherical power and the astigmatic power as the measurement power are almost the same as the prescription power of the wearer as in the comparative example of FIG. That is, the objective of the present invention is achieved in the progressive-power lens of the second embodiment as in the first embodiment.

As described above, in the progressive-power lens of this embodiment, the optical performance in the wearing state is good, and a lens power can be obtained by a lens meter so that the measurement power is almost equal to the prescription power. The frequency measurement can be easily performed. Of the reference point for distance and the reference point for near distance, which measurement reference point is used for power measurement depends on whether the lens is a progressive power lens with distance prescription or near-field treatment. It often depends on whether it is a progressive power lens. In the case of a progressive power lens focusing on distance vision, the distance is used as a reference point for the distance, and in the case of a near progressive refractive lens focusing on near vision, measurement is often performed at the near reference point. Whichever measurement reference point is used, the technique of the present invention is essentially the same. Therefore, it is apparent that the present invention can be applied to progressive-power lenses having various specifications without being limited to the above-described embodiments.

Claims

The scope of the claims

1. Compared with the distance area, which is relatively suitable for far vision, along the main line of sight that divides the refractive surface of the lens into a nose area and an ear area in the wearing state. A near area suitable for general near vision, and a surface refractive power of the distance area and a surface refractive power of the near area between the distance area and the near area. In a progressive-power lens with progressive regions that are connected continuously,

The prescription surface formed to correct the optical performance of the transmitted light of the lens has an aspheric shape, and is generated by the surface astigmatism component generated by the prescription surface and the spherical surface or toric surface necessary for correcting the prescription power Progressive refraction characterized in that the average value of the absolute value of the difference from the surface astigmatic difference component is less than or equal to a predetermined value over a predetermined area in the vicinity including the measurement reference point for measuring the lens power Power lens.

2. At least one of the size and shape of the predetermined area is measured by the wearer's prescription, the wearer's use conditions, the specification of the lens as a product, the method of measuring the lens power, and the lens power. 2. The progressive-power lens according to claim 1, wherein the progressive-power lens is determined based on at least one of the specifications of the measuring instrument.

3. The predetermined region is defined as a distance from the measurement reference point in the horizontal direction of the lens to X (mm) and a distance from the measurement reference point in the vertical direction of the lens to y (mm).

I (x ² + y ² ) ^1/2 I≤ 2.5 0

The progressive-power lens according to claim 2, which is a region that satisfies the above condition.

4. At least the second derivative of the function representing the surface shape of the prescription surface is the prescription. The progressive-power lens according to claim 3, wherein the progressive-power lens is continuous over substantially the entire surface.

5. The predetermined area is defined such that the distance from the measurement reference point in the horizontal direction of the lens is X (mm), and the distance from the measurement reference point in the vertical direction of the lens is y (mm).

I (x ² + y ' ^1/2 I≤ 2.5 0

The progressive refraction calendar according to claim 1, wherein the progressive refraction calendar is a region that satisfies the following condition.

6. The progressive power lens according to claim 5, wherein at least the second derivative of the function representing the surface shape of the prescription surface is continuous over substantially the entire prescription surface.

7. The progressive-power lens according to claim 1, wherein the predetermined value is 0.15 diopter.

8. At least one of the size and shape of the predetermined area is measured by the wearer's prescription, the wearer's use conditions, the specifications of the lens as a product, the method of measuring the lens power, and the lens power. The progressive-power lens according to claim 7, wherein the progressive-power lens is determined based on at least one of the specifications of the measuring instrument.

9. The predetermined area is defined such that a distance from the measurement reference point in the horizontal direction of the lens is X (mm), and a distance from the measurement reference point in the vertical direction of the lens is y (mm),

I (x ² + y ² ) ^1/2 I≤ 2.5 0 The progressive-power lens according to claim 8, which is a region that satisfies the following condition.

10. The progressive bending lens according to claim 9, wherein at least the second derivative of the function representing the surface shape of the prescription surface is continuous over substantially the entire processing surface.

1 1. The predetermined area has a distance from the measurement reference point in the horizontal direction of the lens as X (mm) and a distance from the measurement reference point in the vertical direction of the lens as y (mm).

] (x ² + y ² ) ≤ 2.5 0

8. The progressive refraction calendar according to claim 7, wherein the progressive refraction calendar is a region that satisfies the following condition.

12. The progressive power lens according to claim 11, wherein at least the second derivative of the function representing the surface shape of the prescription surface is continuous over substantially the entire processing surface.

1. The progressive power lens according to claim 1, wherein the predetermined region has a substantially spherical shape or a toric surface shape.

14 4. At least one of the size and shape of the predetermined area is determined by the wearer's treatment, the wearer's usage conditions, the specifications of the lens as a product, the method of measuring the lens power, and the lens power. 14. The progressive refraction calendar according to claim 13, wherein the progressive refraction calendar is determined on the basis of at least one of the specifications of a measuring instrument for measuring the temperature.

15. The predetermined area is defined such that a distance from the measurement reference point in the horizontal direction of the lens is X (mm) and a distance from the measurement reference point in the vertical direction of the lens is y (mm).

I (x ² + y ² ) ^1/2 I≤ 2. 50

The progressive-power lens according to claim 14, wherein the progressive-power lens is a region that satisfies the following condition.

16. The progressive power lens according to claim 15, wherein at least the second derivative of the function representing the surface shape of the prescription surface is continuous over substantially the entire processing surface.

17. In the predetermined area, the distance from the measurement reference point in the horizontal direction of the lens is X (mm), and the distance from the measurement reference point in the vertical direction of the lens is y (mm).

I (x ² + y ² ) \ ≤2. 50

The progressive-power lens according to claim 13, wherein the lens satisfies the following condition.

18. The progressive power lens according to claim 1, wherein at least the second derivative of the function representing the surface shape of the prescription surface is continuous over substantially the entire processing surface.